Combined twist tube and friction spindle and process

ABSTRACT

False-twist device for treating yarn that has been textured by means including a twist tube positioned in the throat between two axially parallel rollers, wherein one of the rollers is formed with an axial bore with friction members in the bore, the yarn being directed through the bore and in contact with the friction members after leaving the twist tube, and process for treating the yarn.

United States Patent [191 Stutz Apr. 10, 1973 COMBINED TWIST TUBE AND FRICTION SPINDLE AND PROCESS [75] Inventor: Otto Titus Stutz, Wattwil, Switzerland [73] Assignee: Heberlein & Co. AG, Wattwil,

Canton of St. Goll, Switzerland 22 Filed: May28, 1971 21 Appl.No.: 147,852

[30] Foreign Application Priority Data June 5, 1970 Switzerland ..8423/70 [52] US. Cl. ..57/34 HS, 57/77.45, 57/157 TS [51] Int. Cl ..D02g 1/02, DOZg 1/04 [58] Field of Search ..57/34 HS, 157 TS,

[56] References Cited UNITED STATES PATENTS 3,403,566 10/1968 Mattingly ..57/77.45 X 3,516,240 6/1970 Fain ..57/l57 TS Primary Examiner.lohn Petrakes Attomey-John Thomas Cella ABSTRACT False-twist device for treating yarn that has been textured by means including a twist tube positioned in the throat between two axially parallel rollers, wherein one of the rollers is formed with an axial bore with friction members in the bore, the yarn being directed through the bore and in contact with the friction members after leaving the twist tube, and process for treating the yarn.

5 2 ligures PATENTED APR 1 01973 INVENTOR. 0 77708 67022 COMBINED TWIST TUBE AND FRICTION SPINDLEAND PROCESS This invention relates to the treatment of textile yarns, and more particularly, to a process and apparatus for compensation of internal stresses in textured synthetic textile yarns.

It is known to produce elastic textured textile yarns by temporary high-twisting of thermoplastic multifilament yarns by means of a false-twist device and by heat-setting in the high-twist condition. It is furthermore known to modify the process so that, according to necessity, textured yarns with reduced elasticity, reduced bulk, etc., are obtained.

A disadvantage in the yarns thus obtained is that, when unwinding them overhead, before feeding them to a processing machine such as a knitting machine, undesired crinkling of the yarn occurs which may cause thread breakages and consequent undesirable down time of the treatment equipment. This tendency to crinkle is at least partially due to torsional stresses which have been imparted intentionally for certain uses of the yarn, such as e.g., for yarns for stockings.

Furthermore, a process is known to obtain at least a temporary compensation of internal stresses in yarns which have been textured by temporary high-twisting and heat-setting in the high-twisted condition, the elasticity of which has been reduced by a subsequent second heatsetting. According to this process, the textile yarn is subjected to a further temporary high-twisting, but in a direction opposite to that of the original twist, and without further heat-setting in the hightwisted condition. In the second false-twisting, either a known twist imparter used in the usual false-twist texturing machines with twist tubes, or a likewise known friction twist imparter can be used. In this connection, US. Pat. Nos. 3,267,657 and 3,543,505 are ofinterest'. In any case, this process has the disadvantage that two separate steps are required so that it is a time consuming and thus costly procedure.

I have conceived an apparatus and a process according to which the foregoing difficulties and disadvantages are readily overcome. Thus, I have found that the false-twist in both directions can be effected in a simple way with only one false-twist device, whereby I am able to provide an essentially more economic solution to the problem.

According to the invention, I contribute a combined false-twist device comprising a twist tube and a friction twist imparter, the yarn being first passed through the twist tube and then through deviation members and through the friction twist imparter so that a false-twist is effected in a direction opposite to that of the original twist.

An important feature of the present invention resides in the provision of an apparatus for effecting the process with a twist tube situated in the throat between two axially parallel rollers with tangential contact with the latter, one of the rollers being driven, and wherein the twist tube is pressed against the rollers by means of a permanent magnet. The apparatus is characterized in that one of the rollers contains an axial bore and friction elements and in that means are provided for deviating the yarn upon leaving the twist tube and for passing the same through the bore and pressing it against the friction elements.

There has thus been outlined rather broadly the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of the invention. It is important, therefore, that the claims be regarded as including such equivalent construction as do not depart from the spirit and scope of the invention.

A specific embodiment of the invention has been chosen for purposes of illustration and description, and is shown in the accompanying drawings, forming a part of the specification, wherein:

FIG. 1 is a schematic view of the apparatus of the present invention; and

FIG. 2 illustrates one embodiment of the apparatus in elevation and, partially, in cross-section.

According to FIG. 1, the yarn 1 supplied by a bobbin (not shown) successively passes through a first pair of delivery or feed rollers 2, a heating device 3, the twisttube 4 of the combined false-twist device 5, the deviation elements 7, 7', 7", 7" which divert or change the direction of advance of the yarn, in this case by each. The yarn next passes through the friction twist imparter 8 of the false-twist device 5 and a second pair of delivery rollers 6 wherefrom the yarn is passed to a windup device (not shown). If the yarn is to be submitted to a second heat treatment in order to reduce elasticity after the texturing effected between rollers 2 and twist tube 4, a second heat-setting element 9 can be placed between the deviation elements 7 and 7", these elements being replaceable by pairs of delivery rollers.

The apparatus shown in FIG. 2 includes two rollers 10 and 11 which consist of axially parallel pairs of discs l2, l2 and r 13, 13' with spacing hubs 14 and 15, respectively, rigidly connected with the discs. The discs and hubs may be formed of synthetic rubber, for example. The rollers 10 and 11 each are fixed on shafts 21 and 22, respectively, which are supported by ball bearings in bearing cases 23 and 24, respectively. The shaft 21 is driven by means of a belt 26 running over the driving roller 25 fixed on the lower part of the shaft. In the throats formed by the discs 12, 12' and 13, 13', a twist tube 16 is supported parallel to the axes of the shafts 10, 11 and in tangential contact with the discs. The twist tube is under the influence of a permanent horseshoe magnet, the pole shoes 17, 17' of which extend into the gap between the discs 10, 11. The twist tube 16 presents a central part 18 of greater width consisting of laminated sheets of iron of low magnetic loss characteristics, and a forked heat 19 with a pin 20 passing transversely through the fork gap, around which the yarn is wound once.

For convenience, the roller 10, the shaft 21, the top part 27 thereof, the bearing case 23 and the driving roller 25 are shown in axial cross-section. The shaft 21 is formed with an axial bore 28. An upper mounting block 27 and the lower part of the drivingroller 25 are formed with recesses 29 and 30, respectively, in each of which an annular friction body 31, 32 have been placed and are secured against falling out by protrusions 25' and 27'. The friction bodies 31, 32 may consist of rings of a material with high friction coefficient with respect to the textile yarns, such as e.g., natural or synthetic rubber or of other suitable synthetic material.

In order to be able to impart different numbers of turns by means of this friction twist imparter according to the titer of the yarn, exchangeable friction elements 31, 32 of different thickness may be inserted into the gaps 29, 30.

It is useful in certain cases to subject the yarn, while it is passed through the friction twist imparter, to a stretch of between 1 and percent. In this case, a separate drivable delivery member for introducing the yarn into the bore 23 and for removing it therefrom must be provided, the delivery speeds of which are proportioned so that the desired stretch is obtained.

The process of the present invention is useful for the treatment of textured synthetic multifilament yarns consisting of polyamides, e.g., poly hexamethylene adipamide (polyamide 66), condensation products of epsilon-aminocaproic acid (polyamide 6) or of 11- aminoundecanoic acid (polyamide 1 l furthermore of polyesters (polyethylene glycol terephtalate), vinyl compounds (polyacrylonitrile) or polyolefines. The process is particularly suitable for yarns to which a relatively low number of twists has been imparted during false-twist texturing and on which heat-setting has been effected at relatively low temperature. Such yarns which are useful in the fine hosiery industry present rather high torsional stresses which must be temporarily compensated before introducing the yarns into the processing machine. In the ready hosiery, a reformation of these torsional stresses can be effected when developing crimp by steaming, treatment with hot air or with hot water.

From the foregoing description, it will be seen that I contribute a method and a single apparatus for effecting false-twisting of the same yarn in opposite directions; and that a single or double heating of the yarn may be effected without altering the twisting apparatus. It will also be appreciated that, if desired, the deviation elements may be arranged so that the yarn is fed into the shaft 21 in the direction opposite to that described, i.e., in an upward direction, as viewed in FIGS. 1 and 2.

I believe that the construction and operation of my novel apparatus will now be understood and that the advantages of my invention will be fully appreciated by those persons skilled in the art.

Iclaim:

1. Process for compensating internal tensions in a yarn which has been textured by temporary high-twisting and heat-setting in the high-twisted condition by imparting to the yarns a further temporary high twist without heat-setting in opposite direction, characterized in that both high-twisting treatments are effected by means of a combined false-twisting device comprising a twist tube and a friction twist imparter, the yarn being first passed through the twist tube and then over deviation members and through the friction twist imparter so that false-twist in the opposite direction is produced, and'stretching the yarn by an amount of the order of l to 10 percent while it passes through the friction twist imparter.

2. alse-twist device for compensating internal tensions in a yarn which has been textured by temporary high-twisting and heat-setting in the high-twisted condition with a twist tube (16) lying in the throat between two axially parallel rollers (10, 11) in tangential contact with the rollers, one of the rollers being driven and the twist tube being pressed against the rollers b means of a magnet, characterized in that one of the rollers (10) is formed with an axial bore (28) and friction members (31, 32) and in that delivery means (7, 7', 7", 7") are provided for deviating the yarn leaving the twist tube and for passing the same through the bore under pressure against the friction members.

3. Apparatus according to claim 2, characterized in that at least one of the friction members is formed of a material with a high friction coefficient with respect to the yarn.

4. Apparatus according to claim 2, characterized in that friction members of various thicknesses are exchangeably insertable in the friction twist imparter.

5. Apparatus according to claim 2, characterized in that separately drivable delivery means are provided for introducing the yarn into the bore (28) and for evacuation of the yarn from the same. 

1. Process for compensating internal tensions in a yarn which has been textured by temporary high-twisting and heat-setting in the high-twisted condition by imparting to the yarns a further temporary high twist without heat-setting in opposite direction, characterized in that both high-twisting treatments are effected by means of a combined false-twisting device comprising a twist tube and a friction twist imparter, the yarn being first passed through the twist tube and then over deviation members and through the friction twist imparter so that false-twist in the opposite direction is produced, and stretching the yarn by an amount of the order of 1 to 10 percent while it passes through the friction twist imparter.
 2. False-twist device for compensating internal tensions in a yarn which has been textured by temporary high-twisting and heat-setting in the high-twisted condition with a twist tube (16) lying in the throat between two axially parallel rollers (10, 11) in tangential contact with the rollers, one of the rollers being driven and the twist tube being pressed against the rollers b means of a magnet, characterized in that one of the rollers (10) is formed with an axial bore (28) and friction members (31, 32) and in that delivery means (7, 7'', 7'''', 7'''''') are provided for deviating the yarn leaving the twist tube and for passing the same through the bore under pressure against the friction members.
 3. Apparatus according to claim 2, characterized in that at least one of the friction members is formed of a material with a high friction coefficient with respect to the yarn.
 4. Apparatus according to claim 2, characterized in that friction meMbers of various thicknesses are exchangeably insertable in the friction twist imparter.
 5. Apparatus according to claim 2, characterized in that separately drivable delivery means are provided for introducing the yarn into the bore (28) and for evacuation of the yarn from the same. 